Centrifugal valve assembly



A ril 21, 1953 R. H. CONDELL' CENTRIFUGAL VALVE ASSEMBLY Filed Oct. 22,1948 Inventor ymond hf Condel/ 2 a Attorney Patented Apr. 21, 1953'-u,:1v1reo STATES PATENT OFFICE .ciinrmrcezfi il iie ASSEMBLY Raymond3H. (Jonas-11, Philadelphia, Pa., assignor to "The Sharples:Oorporation, a corporation in! Delaware Application was 22, 1948,serial no. 555.998

(01. in -sol This invention relates to a centrifu'gally operated valveparticularly adapted for use in centrifuges. H g I It iscommon practiceto construct certain types of centrifugal machines in such a manner thatthe bowl rotates about a vertical axis. In this event, the liquid thatis to be clarified or separated is fed to the centrifuge upwardlythrough the bottom of the rotating bowl. As long as the fmachine isoperating above a certain speed, the liquid that is fed in at the bottomruns out at the top after clarification or separation, a the case maybe.However, when the machine is stopped, the effect of gravity becomesgreater than the substantially horizontal effect of centrifugal force,so that any liquid remaining in the bowl ordinarily flows out the bottom'of the centrifuge. This result must be avoided in the preparation'ofcert'ain serums in order to prevent contamination of the liquid inthe bowl and for this reason the remaining liquid should not come incontact with any surface outside the bowl, since such outside surfacemay not be sterile.

In virus preparation, it is customary to feed liqu-id containing thevirus through the centrifuge at low capacity. The high centrifugal forceof the rotating bowl retains the virus concentrate against the insidewallio'f the bowl, whereas relatively virus-free 'liquid'is dischargedfrom the top of the bowl. In this operation, the liquid is fed forperiods as long as eight hours in order to gradually accumulate theconcentrated virus in the bowl. During the run, the separated liquid isremoved, thus leaving the concentrate in the bowl and it is thisconcentrate which must be maintained in a sterile condition, not .onlywhen the centrifuge is operating at normal speed "but when the machineis'decelerating, as well as when the bowl has completely come to rest.Furthermore, it is important that the bowl may be removed from thecentrifuge without danger or the virus concentrate'being lost from thebowl. The present construction contemplates provision of an automaticcheck valve located at the bottom of the bowl, which completely preventsdraining the bowlthrough the bottom thereof.

A primary object therefore, of my invention, is to provide'acentrifugally operated check valve for centrifuges which is simple,inexpensive to manufacture, and which may be kept thoroughly sterile at.all times. i V

A further object of the invention is to provide an annular resilientring adapted to close the intake passages at the bottom of the bowl whenthe bowl is stationary or substantially so, but

2 open when the rotational speed of the bowl approaches its normaloperatingvalue.

A further object is to provide a resilient check valve for eachindividual feed passage at the bottom of the bowl, the function of thecheck valves being to close the passages to prevent out- Ward flow ofliquid but to permit inward flow of liquid when the centrifugal'force issuflicient to spring the valves away from theirseats.

Further objects will'be apparent from the specification and drawings inwhich:

Fig. 1 is a sectional detail showing a centrifugal valve constructed inaccordance with the invention, installedin a centrifuge bowl;

Fig. 2 is a view similar to Fig. '1 but with the valve in an expandedposition as would occur when the bowl is rotating athig h 'speed;

Fig. '3 is an exploded view showing in perspective the elements of thevalve construction; and

Fig. 4 is a sectional view on a reduced scale of a modified form ofcentrifugally operated valve.

Referring now more particularly to the drawings, the structure at thebase of the centrifuge bowl illustrated therein comprises a bowl bottom10 having a downwardly depending boss I I, which is provided withavertical bore 1l-2 through which the liquid is fed to the centrifugebowl. The bowl .shell 13 is threadedly connected to an .outer .annularring M on the .bowlwbottom l0 and is adapted to rotate with bottom H) atrelatively highspeeds. ,Acup-shaped member I5 is mounted in alignmentwith bore l2 and compressed tightly against a counterfacedsurface it of-bottom iii through an annular gasket -lzl. Retainer 18 is adapted .toclamp member tightly against the gasket by means of threads I 9.

In order to bring the liquid up to the speed of the bowl as rapidly aspossible after the liquid is fed into the bowl, a plurality of vanes 01'wings 21B are positioned in axial alignmentwith the bore 1:2 andretained in the hollow portion -of .cup 115. The wings'ar-e preventedfrom rotating relatively with respect to the bowl'gas'sembly by means ofa pin 21 pressed into the bore-ofcup 45.

The upper :portion 15a .of the cup I5 is of reduced diameter and isprovided with a plurality .of radial ports 22 which terminate :at theirouter ends in an annular groove 23 adapted to receive a flexible ring 24which may be made of rubber or similar material. The concave curvatureof groove 23 may pref-erably'be of the same radius as thecross-sectionalcurvature of ring 24 shown clearly in Figs. 1 and 2. Itwill be understood that the cross-section of one side of ring member 24is circular as shown in Fig. 2. However, any

other cross-sectional shape may be employed, providing satisfactorysealing between ports 22 and the ring 24 is obtained.

The bore 25 of retainer 18 is greater than the diameter of the upperportion la to provide ample passage for inflowing liquid. Retainer I8 isalso provided with an annular internal groove 26 which is in registrywith the ports 22, 22. Slots 27, 21 in-retainer [8 enable it to bequickly assembled or dis-assembled by means of a suitable tool.

Referring now to Fig. 4, the modified embodiment shown therein may besubstituted in its entirety for cup [5 and retainer I8, together withthe valve '24. Valve body member 39 is provided with external threads 3!adapted to cooperate with threads [9 and thereby to provide a tight sealwith bowl bottom Ill through gasket l1. Body 30 is likewise providedwith a plurality of radially extending ports 32 which connect the bore33 of body 30 with feed passage l2. The upper portion of body 32 has aslight overhang at 39' to which a plurality of flat springs 34, 34 areattached in a downwardly depending position by means of screws 35, 35.The lower end of each spring 34 carries a plug or stopper 36 each ofwhich is adapted to register with an individual port 32. The materialused in the plugs will depend upon the particular liquid beingcentrifuged and may be rubber, leather, or some form of syntheticplastic which will be impervious to any chemical action likely to takeplace. The top of body 33 is drilled at 3T, 31 to accept a suitable toolfor removing or tightening the member 30 against bowl bottom Hi.

It will be understood that the elasticity of springs 34 is so calculatedthat ports 32 will be closed by stoppers 36 at all speeds substantiallybelow normal operating speed of the bowl.

In operation, the flexible ring 24 or the individual springs 34 tightlyseal ports 22 or 32 as the case may be, as shown in Figs. 1 and 4. Thisprevents any flow of liquid through the ports when the bowl isstationary or substantially below normal operating speed. As the bowl isbrought up to speed, centrifugal force expands the ring or distendssprings 34 to open ports 22 and 32. In the case of the flexible ring, itwill be observed that centrifugal force causes the ring to expandradially so that it fits in the annular seat 26. Likewise in the case ofthe spring 34, outward radial movement thereof is limited by the insidewall of bowl shell 13 as shown in Fig. 4. The speed at which the ports22 and 23 are opened depends upon the physical characteristics of thering or the springs, as the case may be. It is only necessary that theports be closed when the vertical component or" the force acting on theliquid in the bowl due to gravity, bears such a relation to thehorizontal component due to centrifugal force, that the liquid in thebowl will recede sufiiciently from the norm-a1 operating position (inwhich the liquid assumes the shape of an annulus around'the' innerperiphery of the bowl and having a nearly vertical inner wall spacedradially outwardly away from ports 22 and 32) to come in contact withthe check valve assembly.

It will thus be apparent that I have provided an extremely eflicientautomatic valve for a centrifuge, which absolutely prevents anyundesired return of liquid from the bowl when it is station- 2,635,617if' r ary or when it is slowed down. All the parts of the valve assemblyare likewise simple and easy to manufacture. The flexing of the rubber Oring is the only movement of the valve in this embodiment and there isno metal-to-metal contact likely to wear and cause leakage.

Having thus described my invention, I claim:

1. A centrifugal valve assembly comprising a rotating member, a radiallyextending port in said member adapted to provide fluid passage throughsaid member, a resilient valve member mounted at the radially outwardextremity of said port and adapted to close said port, a retainingsurface rotatable with the rotating member in radial outward spacedrelation to the valve member, and a fluid passage between the retainingsurface and the port, the retaining surface, fluid passage and valvemember being so arranged that when the rotating member is stationary thevalve member is resiliently pressed onto the terminus of the port toclose said port, but when the member rotates at a relatively high speedcentrifugal force causes the valve member to move radially outward to beheld in a predetermined open position by the retaining surface, toprovide fluid communication through the passage and the port.

2. A centrifugal valve assembly comprising a rotating member, aplurality of radially extending ports in said member adapted to providefluid passage through said member, a resilient ring positioned tosurround and close the radially outward termini of said ports, anannular retaining member rotatable with the rotating member, an internalwall on said retaining member defining an annular groove in registrywith the outer termini of the ports in the rotating member and in radialoutward spaced relation thereto, and a fluid passage between therotating member and the retaining member, the retaining member,resilient ring and fluid passage being so arranged that when therotating member is stationary the ring is resiliently pressed onto theterminus of the ports to close said ports, but when the member rotatesat a relatively high speed centrifugal force causes the resilient ringto move radially outward to be held in a predetermined open position bythe retaining member, to provide fluid communication through the passageand the ports.

3. Apparatus in accordance with claim 2, in which the rotating member isprovided with an annular groove adapted to receive the resilient ring.

4. Apparatus in accordance with claim 1, in which the resilient valvemember comprises a flat spring mounted on said rotating member, and aplug on said spring adapted to register with said port.

RAYMOND H. CONDELL.

References Cited in the file of this patent UNITED STATES PATENTS NumberName Date 416,320 Bergner Dec. 3, 1889 445,066 DeLaval Jan. 20, 1891842,257 Sharples Jan. 29, 1907 850,954 McLean Apr. 23, 1907 l,75l,982|Dunham Mar. 25, 1930 2,456,347 Vogel Dec. 14, 1948 2,482,570 Acton Sept.20, 1949

